[wasm] OOB traps: build protected instruction list during codegen

src/compiler/code-generator.cc

Index: src/compiler/code-generator.cc
diff --git a/src/compiler/code-generator.cc b/src/compiler/code-generator.cc
index a7c2c65c0856a72fd33f832528c42eca167bd5c9..c6ad74a70d092f74f44f48c08d56a17937e57ea9 100644
--- a/src/compiler/code-generator.cc
+++ b/src/compiler/code-generator.cc
@@ -33,8 +33,10 @@ class CodeGenerator::JumpTable final : public ZoneObject {
   size_t const target_count_;
 };
 
-CodeGenerator::CodeGenerator(Frame* frame, Linkage* linkage,
-                             InstructionSequence* code, CompilationInfo* info)
+CodeGenerator::CodeGenerator(
+    Frame* frame, Linkage* linkage, InstructionSequence* code,
+    CompilationInfo* info,
+    trap_handler::ProtectedInstructionList* protected_instructions)
     : frame_access_state_(nullptr),
       linkage_(linkage),
       code_(code),
@@ -57,7 +59,8 @@ CodeGenerator::CodeGenerator(Frame* frame, Linkage* linkage,
       ools_(nullptr),
       osr_pc_offset_(-1),
       source_position_table_builder_(code->zone(),
-                                     info->SourcePositionRecordingMode()) {
+                                     info->SourcePositionRecordingMode()),
+      protected_instructions_(protected_instructions) {
   for (int i = 0; i < code->InstructionBlockCount(); ++i) {
     new (&labels_[i]) Label;
   }
@@ -71,6 +74,16 @@ void CodeGenerator::CreateFrameAccessState(Frame* frame) {
   frame_access_state_ = new (code()->zone()) FrameAccessState(frame);
 }
 
+void CodeGenerator::AddProtectedInstruction(int instr_offset,
+                                            int landing_offset) {
+  if (protected_instructions_ != nullptr) {
+    trap_handler::ProtectedInstructionData data;

[titzer, 2016/11/30 17:31:12]

This can be a little shorter if you either introduce a constructor or just use
the inline {} struct value. Also I think it's more efficient to use
emplace_back().

[Eric Holk, 2016/11/30 20:16:19]

Done.

+    data.instr_offset = instr_offset;
+    data.landing_offset = landing_offset;
+    protected_instructions_->push_back(data);
+  }
+}
+
 Handle<Code> CodeGenerator::GenerateCode() {
   CompilationInfo* info = this->info();